The maximum buy is the highest price that preserves the required margin. Write it before the show, the auction, or the offer conversation.
The structure
Maximum buy = expected sale price − selling fees − shipping − supplies − other costs − required profit.
The field shortcut
For typical fee assumptions: (sale price × 0.85) − shipping − desired profit. That 0.85 factor is a quick field estimate, not a permanent marketplace rate.
Use it well
- Base the expected sale on comparable sold listings.
- Lower the sale estimate when grade or problem status is uncertain.
- Include insurance, signature, grading, or promoted-listing costs when they apply.
- Once the maximum is written, do not let auction fever move it.
Marketplace fees and postage change. Rebuild the factor from current rates before using it with real money.